Bidirectional positioning device



July 28, 1964 vC. R. RHODES BIDIRECTIONAL POSITIONING DEVICE Filed July13, 1960 I8 ROTATION INVENTOR. CHESTER R. RHODES BY Km AGENT UnitedStates Patent 3,142,789 BIDIRECTIONAL POSITIONING DEVICE Chester R.Rhodes, 206 W. Stardell St., Whittier, Calif. Filed July 13, 1960, Ser.No. 42,630 11 Claims. (Cl. 317-189) My invention relates to anelectro-mechanical device and particularly to an electrically-energizedmagneticallyactuated bidirectional stepping device.

While the desirability of having a positioning device capable ofactuation in either direction of rotation according to selectedenergization it is evident the prior art has been largely incapable offulfilling the need.

- I have found it possible to accomplish selective bidirectionalstepping in a novel structure having a relatively few parts, which has astrong end of step torque, a high torque to electrical power input ratioand a brake action upon the output shaft when a step is not in progress.

' The structure is comprised of a magnetic core having three axiallyspaced pole pieces, each having plural aligned circumferentiallyprojecting poles. Between the pole pieces are two separate solenoids. Anarmature having slats of magnetic material operationally aligned withsaid poles surrounds the same. Each of said slats is shaped to providean air gap of minimum reluctance for rotation of the armature in onedirection, but not in the other direction. By energizing one of saidsolenoids with electric current the armature is caused to rotate in onedirection and by energizing the other solenoid, in the oppositedirection.

Substantially midway in the rotational step an auxiliary electricalcontact is closed. This energizes the second solenoid. Because of thealtered magnetic configuration at this time, the magnetomotive forceexerted by both solenoids is additive. This gives desirable certainty toaccomplishment of the step under adverse electrical, magnetic ormechanical conditions.

An output shaft journaled free of the armature has a flatted gear. Apair of oppositely disposed pawls are attached to the armature by asingle pin so positioned with respect to the flatted gear that anexcursion of the armature rotates the gear a fraction of a revolutioncorresponding to the pitch between the teeth of the gear. One projectionat one extremity of what has been characterized as a pair of pawlsengages the teeth of the gear for rotation in one direction and theopposite projection engages a tooth of the gear for rotation in theopposite direction.

In order that the output shaft may remain stationary when not beingstepped regardless of severe vibration or other extraneous circumstancesa polygonal drum is attached to that shaft in mechanical phase with theflatted gear. A pair of spring biased brake arms bear upon this drum andso retain the output shaft against spurious rotation to whatever degreemay be desired. The degree of retention is determined by the forceexerted by the spring.

An object of my invention is to provide a bidirectional positioningdevice in which the direction of rotation is completely selectable bythe mode of electrical energization.

Another object is to accomplish bidirectional stepping with a device ofrelatively few parts.

Another object is to accomplish stepping with a strong terminal force.

Another object is to provide a relatively high torque for stepping inrelation to the electrical power employed.

Another object is to provide immobilization of the stepped shaft whenstepping is not in progress.

Other objects will become apparent upon reading the following detailedspecification and upon examining the accompanying drawings, in which areset forth by way of illustration and example certain embodiments of myinvention.

FIG. 1 shows a side elevation of my bidirectional positioning device,

FIG. 2 shows an end elevation of the same,

FIG. 3 shows a sectional elevation of the magnetic structure alongsection 33 in FIG. 1,

FIG. 4 shows the variation of actuating tor que as a function ofrotation,

FIG. 5 is a schematic electrical circuit diagram. In FIG. 3 numeral 1indicates a central cylindrical core, having low magnetic retentivityand formed of a material such as Armco ingot (soft) iron. In FIG. 1, 2is the left end pole piece and 3 is the right end pole piece. Thecentral pole piece 4 has an axial thickness approximately three timesthat of either end pole piece. The central pole piece 4 is shown in endview in FIG. 3. Three poles 4, 5 and 6 are seen extending radially fromcore 1. Similar and aligned poles are also found on the end pole pieces2 and 3. All pole pieces are preferably one piece with core 1; all beingmachined from a single piece of stock, although any method by which thismagnetic structure may be fabricated from individual pieces with lowreluctance joints is satisfactory.

Left coil, or solenoid, 7, has the function of initiating motion of thearmature in one direction and of supplying additional magnetomotiveforce to aid the right coil, or solenoid, 8, in completing motion in theopposite direction. By the same token, coil 7 aids the motion initiatedby coil 8. For 28 volt operation each coil may be formed ofapproximately 3,200 turns of #33 AWG wire, the resistance thereof beingapproximately 50 ohms. Both of these coils are wound in the samedirection; aiding. Separate connections are brought out for connectionaccording to FIG. 5.

Looking at my device from the end shown in FIG. 2, for counterclockwiserotation coil 7 is energized first. This occurs because of the lowmagnetic reluctance at the coil 7 end of the device occasioned bycircumferential extension 12 on slat 11 and corresponding extensions onthe other slats, all to be further explained. In an analogous manner,for clockwise rotation coil 8 is energized first.

Left armature end-disk 9 is circular and is constructed of anon-magnetic material such as aluminum, or perhaps of a structurallystable insulator, such as diall phthalate, Myclex, etc. This disk servesto support the several slats 11, 14 and 15, all of which are seen inFIG.3. The other end of each slat is supported by a similar armatureend-disk 10. These end-disks are fastened to the core structurepreviously described for rotation by bearings. These may be ballbearings, or phosphor-bronze or graphite-bronze sleeve bearings.

As will be noted particularly in FIG. 3, each of the armature slats 11,14 and 15 have a circumferential curvature consonant with the armatureend-disks 9 and 10 and also with the outer circumference of poles 4, 5and 6. This is so that the magnetic reluctance between the poles and theslats will be a small amount. The manner in which rotation in onedirection is accomplished by exciting one coil first and rotation in theopposite direction by exciting the other coil first is seen by a carefulexamination of FIG. 1, in combination with FIG. 3. It is seen thatextension 12 causes the reluctance to be considerably less to the lowerpole of pole piece 2 (the one behind pole 5; that is, in alignmenttherewith, in FIG. 3) than to the upper and forward pole thereof(aligned with pole 6). When coil 7 is energized the flux flows particularly through the part of core 1 under that solenoid, out

through center pole "piece 4, through slat 11 and the circumferentialextension of the same 12 and back through end pole piece 2. Whether theflux flows in the direction indicated, or in the opposite direction isunimportant; the point is that the path outlined is theone of lowestreluctance. The magnetic force thus produced tends to reduce thereluctance even more and so the armature revolves counterclockwise asviewed in FIG. 2, as has been mentioned.

By the same process, but because of the .opposite circumferentialdirection of extension 13, when coil 8 is initially energized themagnetic flux flows around the right hand side of the structure of FIG.1 and motion of the armature in the clockwise direction occurs. It is tobe noted that my bidirectional motions occur because of assymetricmagnetic structures and not because of magnetic polarization whereinopposed coils produce a flux that either attracts or repels a permanentmagnet member. Slats 11, 14 and 15 are also formed from non-retentiveArmco ingot iron, as was the stationary magnetic structure.

A left stationary end support 16 is provided as part of an outer frameof my device. Attached to it is a tube 17 through which externalconnections from the coils, etc. are brought beyond the rotatablearmature. .A circumferential slot is cut in the left armature end-disk 9so that this member may rotate unimpeded as far as rotation is required.A specific mechanical stop 18 in the form of a projection inward fromend support 16 extends into the again circumferentially slotted armatureend-disk 9. This. second slot has a specific circumferential length thatlimits the excursion of the armature in either direction to an arc ofmotion suited to progress the pawl and gear mechanism to be laterdescribed.

Right stationary end support 19 has the same general nature as the leftsupport 16 and in addition serves to mount the remaining elements of mydevice. The two end supports are joined structurally by three spacerrods. These have not been shown in FIG. 1 in order that the novelmagnetic structure would be clearly illustrated. Considering nowparticularly FIG. 2, the drive pawl is shown at 20. The projections ateach extremity will be noted. The mechanism is shown in the extremeposition for stepping motion counter-clockwise. The pawl is driventhrough pin 21, which pin is attached to right armature end disk 10.Flatted gear 22 is fastened to output shaft 23, which latter has abearing in right stationary end 19. The output shaft is colinear withthe axis of the armature but is not directly connected to the armature.The only connection is through pawl 20 and gear 22. As shown, the pawlhas just completed a counterclockwise excursion against one of the teethof the gear; having advanced the gear and output shaft one step, such as36, one-tenth of a circumference. Gear 22 is shown with ten teeth. Thebearing for the output shaft may be any of the types previouslymentioned.

A brake drum 24 has a polygonal periphery of ten flats. These arealigned with the flats of the flatted gear 22. Right brake arm 25 andleft brake arm 26 both press against flats of the drum during times ofnon-actuation. In the actuated position of FIG. 2 the left arm isremoved from the drum. This occurs because the upper projection of thearm is contacted by pawl 20 in its actuating excursion. From FIG. 1 itwill be noted that brake drum 24 is positioned to the right of flattedgear 22 and that therefore the extension 27 extends to the left in orderto engage pawl 20. The right brake arm also has an upper projectingextension, 28.

A tension spring 29 is attached to each of brake arms 25 and 26relatively near the bottom thereof. This causes a constantly exertedforce against brake drum 24. This is from both arms when the device isnot being actuated and by one when it is being actuated, as shown inFIG. 2. The spring constant is chosen to provide a necessary andsufficient braking effect upon the output shaft, but such as to bewithin the torque capabilities of the magnetic elements. Such a springmay be fabricated in many ways; one example being ten convolutions ofapproximately No. 26 AWG. spring steel wire, with a diameter of theorder of one-eighth inch.

The brake arms 25, 26 are attached to stationary end support 19 by meansof pivot pin 30. Thus spaced from the support and held under the head ofthe pin, the arms are positioned in line with the drum 24. Each of thearms have a hub thickness only half of the thickness of-the arms andthese hubs are offset on left and right arms so that both fit on the pinwithin the axial-distance equal to the thickness of only one brake arm.

While considerable choice of materials is possible for the recitedelements, I have employed bronze for the brake arms, duraluminum for thestationary end supports and machine steel of appropriate hardness forthe pawl, flatted gear, brake drum and shafts.

Auxiliary contacts cam 32 is the actuating element of the auxiliarycontacts group employed to give high terminal torque. It surmountsarmature slat 14 near the armature end-disk 10. This is shown in fulllines in FIG. 1 and in dotted lines in FIG. 2. It is centrally locatedwith respect to slat 14, circumferentially. It is constructed ofaninsulator having durable mechanical properties, such as linenBakelite.

Circumferentially removed from the central rest posi tion of thearmature slat 14 are movable left auxiliary contact 33 and stationaryleft auxiliary contact 34. These are mounted in similarly identifiedcontact arms 35 and 36. The contacts may be of silver and the arms ofberyllium copper. A left auxiliary contact support of linen Bakelite orequivalent 37 is attached to right stationary end support 19 relativelyfar removed from the rest position of slat 14. Upon support 37, doubleinsulated support 38 is mounted. The latter holds both contact arms 35and 36, insulated one from the other.

A right auxiliary contact support 39 is provided symetrically oppositethe left support 37. Right contacts and arms are also provided,positioned as mirror images of the left contacts and arms previouslydescribed with respect to the central rest position of slat 14., Theright contacts and arms are not seen in either FIGS. 1 or 2 because ofpositions behind other important elements. However, the placement andfunction thereof is evident.

Both the left and the right arms of the movable designation are movedtoward the corresponding stationary auxiliary contacts by cam 32 whenthe armature has completed approximately half of its full excursion. Itwill be understood that these elements can be proportioned andpositioned so that this is readily possible. The situation is thesamewhether the armature excursion is to the right or the left (in FIG.2). I

FIG. 4 shows the result of such auxiliary contacting and FIG. 5 thecircuit diagram of the necessary connections.

In FIG. 5 a common electrical input terminal 55 connects to the centerconnection of a series-aiding arrangement of solenoidal coils 7 and 8.Terminal 56 is connected to a source of electric current along withterminal 55 when counter-clockwise motion of the armature is desired.When the resulting excursion due to excitation of coil 7 has been halfaccomplished movable auxiliary contact 33 contacts fixed contact 34. Itis then seen that a circuit is completed through coil 8 with respect tothe energized terminals55 and 56. This is so directed as to increase thetotal magnetomotive force acting upon the several armature slats andsince these have now passed beyond the initial slat assymetry withrespect to the poles of the solenoid magnetic circuit the magneticeffect is to cause rotation until the maximum area of slat and polecoincide. V

For rotation in the other direction the opposite set of auxiliarycontacts are mechanically closed. This set is generically identified byreference numeral 39. The mo? tion in this second direction is initiatedby connecting a source of electric current between contacts 55 and 57.This initially energizes coil 8, and after switch 39 closes, coil 7also, in aiding relation. Capacitor 58 is for arc extinguishment and maybe of half microfarad capacitance with a voltage rating of 400 volts ina practical case.

In FIG. 4 the torque exerted by the magnetic circuit withone coil aloneenergized and starting from the central rest position of the armature isshown by curve 51. The torque, as measured in foot pounds, is theordinate and the abscissa is the rotation of the armature, in degrees ofangle rotated through. Curve 51 has an initially relatively high valuebecause of the asymmetry of the armature slats with respect to the polesand the fact that the force exerted between the two is largelytangential. At a degree of rotation that may be selected by theadjustment of the space between mating contacts, such as contacts 33,34, and importantly by altering the length of cam 32, these contactsclose and the second coil is also energized. In FIG. 4 this closureoccurs at approximately 18. The torque is now more than doubled itsprior value at the 18 rotation point and decreases somewhat as fullrotation is reached according to curve 52. Curves 51 and 52 are frompractice. In this way it is seen how I accomplish high terminal torque.

It will be understood that the armature is returned to its centralposition by the force of tension spring 29 exerted through arms 25 or 26and projections 27 or 28 (depending upon the direction of rotation) uponpawl 20 and hence pin 21.

I have also provided a homing contact and self-interrupting arrangementcomprised of elements to now be described; Element 40 is a stationaryhoming contact and 41 a movable homing contact. These are of silver.These are mounted on movable homing contact arm 42 and a stationaryditto 43, both of beryllium copper. An asymmetric step cam 44 is formedof linen Bakelite and is mounted centrally of movable contact arm 42. Ahoming contact actuating lever 45 coacts with the step cam. The lever isprovided with a fulcrum near the center thereof in the form of pin 46,which is fastened to right stationary end support 19. The upper end oflever 45 contacts a lower extremity of armature end-disk 10.

7 Contact 40 and 41 are normally closed, but open the common coilcircuit (55) each time the armature turns. This provides aself-interrupting aspect, so that a prolonged application of voltageacross either pair of actuating terminals of the device results in onlya pulse flow of current of sufficient duration to actuate it. If pulsesare provided in the form of excitation provided this contactarrangementis not required.

It will be understood that an important application of my device is tostep multicontact switches from one contact to another. One example is athree-gang Wafer type rotary switch assembly, each Wafer having tencontacts (corresponding to the ten position flatted gear).

In order that a homing, or return to original position aspect beprovided, the actuating voltage is fed through a switch wafer having tenpositions but only nine contact balls. Repeated actuation thus producesa rotational response save on the tenth position, which is thusidentified be inoperability, and operation resumed by an additionalshunting circuit that is closed manually or by equivalent automaticmeans.

In common withthe prior contact construction, 47 is the stationaryhoming contact support and may be constructed of linen Bakelite.Similarly, element 48 is the movable homing'contact support.

Certain modifications of my invention are possible.

The auxiliary contacts 33 and 34 are required to be open during thefirst part of any excursion of the armature. .These have been describedas normally open in themselves and as appropriately closed by cam 32contacting the movable contact 33 at half way through the excursion.This construction maybe reversed by simple mechanical interchange andthe contacts held openby the presence of the cam 32 and the appropriateone closed by the cam moving away from it.

Brake drum 24 may be provided with shallow holes in the center of eachflat and the arms 25, 26 provided the mating projections which then actto secure the output shaft from rotation save when the flatted gear isrotated a the rotation excursion, insuring that a positive action willbe completed.

Other applications of my device consist of supplying relative power inincrements for computer-type encoding, to position potentiometers orother variable resistors at specific values, and to operatemultiposition valves.

Other modifications may be made in arrangement, size and proportions ofthe illustrative embodiment shown without departing from my invention.

Having thus fully described my invention and the manner in which it isto be practiced, I claim:

1. In a device having an armature and a magnetic structure internalthereto for rotation of said armature by magnetic force to a terminalamplitude,

' first means for increasing the torque upon said armature at saidterminal amplitude comprising,

plural second means disposed upon said magnetic structure for providingmagnetic force,

third means to energize a second means,

and fourth means mechanically related to said armature to energize anadditional said second means upon rotation of said armaturesubstantially half of said terminal amplitude of rotation.

2. The device of claim 1 in which said plural second means for providingmagnetomotive force comprise plural coils related to said magneticstructure for separate initial energization to initiate rotation of saidarmature in 0pposite directions.

3. In a rotary magnetic device having an armature and a magnetic circuitstructure having aligned poles for the rotation of said armaturepartially around said structure,

first means for providing increased torque at the terminal amplitude ofsaid rotation comprising a first and a second source of magnetomotiveforce, second means to energize said first source,

third means to energize said second source, mechanical meanscircumferentially related to said armature to actuate said third meansupon rotation of said armature an amount less than terminal amplitude;

said second source related to said magnetic circuit structure to provideadditional magnetomotive force upon said armature from said less thanterminal amplitude to said terminal amplitude of rotation.

4. The magnetic device of claim 3 having, in addition, a polygonal drummechanically related to said armature and a pair of mechanically biasedbrake arms bearing upon said drum to retain said drum at terminalamplitude of rotation in the absence of further said magnetomotiveforce.

5. In a rotary electro-rnagnetic device having a rotationally asymmetricarmature and a rotationally symmetric magnetic circuit structurecoactive therewith for bi-directional rotation of said armature byreluctance reduction,

means for providing increased terminal torque for a given armaturerotation comprising operationally interchangeable first and secondelectrical means disposed within said armature and upon said magneticcircuit structure for providing magnetomotive force,

' electrical contacts connected to said second electrical meansmechanically related to said armature to actuate said electricalcontacts upon rotation of said armature an amount less than the full.amount of said given armature rotation;

said second electrical means related to said magnetic circuit structureto provide additional magnetomotive force upon said armature from anamount less than the full amount of said given armature rotation to thefull amount of said given armature rotation in either direction of saidbi-directional rotation.

6. A magnetic device having plural magnetic circuits for selectivelyrotating one armature in either direction comprising a stationarymagnetic structure having more than two groups of radially projectingpoles, an armature having plural circumferential magnetic elementsadjacent to said poles, means to selectively supply said magneticstructure with magnetomotive force, said magnetic elementscircumferentially related to said poles such as to provide a magneticpath of minimum reluctance for rotation in one direction upon one ofsaid magnetic circuits being supplied with magnetomotive force and toprovide a magnetic path of minimum reluctance for rotation in the otherdirection upon the other of said magnetic circuits being supplied withmagnetomotive force.

7. A rotary electro-magnetic device having two magnetic circuits forrotating one armature in either of two directions comprising a centralcore, three spaced disks thereon, each said disk having the same numberof radially projecting poles, an armature having circumferential slatssurrounding said poles, said slats circumferentially related to saidpoles such as to provide a magnetic path of minimum reluctance forrotation in one direction upon one of said magnetic circuits beingsupplied With magnetomotive force and to provide a magnetic path ofminimum reluctance for rotation in the other direction upon the other ofsaid magnetic circuits being supplied with magnetomotive force.

8. A rotary electromechanical device comprising a core having pluralspaced poles, plural electrical means to magnetically energize saidpoles, an armature surrounding said poles, said armature journaled forrotation, plural elements of magnetic material upon said armature forrotating said armature by magnetic attraction of said elements towardsaid poles upon the magnetic energization thereof, each of said elementsdisposed to provide a magnetic circuit of minimum reluctance forrotation of said armature in one direction upon energization of one saidelectrical means and for rotation of said armature in the oppositedirection upon energization of another said electrical means, pluralelectrical contacts connected to said plural electrical means, means toclose said electrical contacts connected to said electrical meansassociated with the magnetic circuit having initially higher reluctanceupon said armature having rotated a part of the full excursion thereof,the magnetomotive force of the electrical means thus energized adding tothe magnetomotive force previously existing.

9. The device of claim 8 having in addition an output shaft and meansmechanically related to said armature to both return said armature toits initial position for the next rotation thereof and to restrain therotation of said armature shaft.

10. A rotary device electrically operable to give a change of positionof an output shaft comprising a magnetic core having axially spaced polepieces, each of said pole pieces having poles aligned one with theother, coils of wire Wound upon said core between said pole pieces, anarmature surrounding said poles, said armature journaled for rotation,slats of magnetic material disposed around said armature for magneticattraction toward said poles upon the passage of an eleotric'currentthrough one of said coils, each of said slats shaped to provide an airgap of minimum reluctance for rotation of said armature in one directionupon passage of current through one said coil and for rotation in theopposite direction upon passage of current through another said coil,auxiliary electrical contacts adjacent to said armature, means attachedto said armature to close the electrical circuit of 3 said .coil thatinitially had the higher reluctance magnetic gap upon said armaturehaving rotated part of the full angular excursion thereof, themagnetomotive force of the coil thus energized adding to themagnetomotive force of the coil originally, energized,,means related tosaid armature to return the same to said initial position for the nextrotative excursion, an output shaft, a toothed element upon said outputshaft, a pawl having a pair of oppositely disposed projections, saidpawl attached to said upon an electric pulse to give a change ofposition to an output shaft comprising a cylindrical core of magneticmaterial having three equally axially spaced pole pieces, each of saidpole pieces having three circumferential poles aligned one with theother, two coils of wire wound for magnetic reinforcement uponelectrical energization upon said core between said pole pieces, anarmature surrounding said poles, said armature journaled for rotationcoaxially with said core, three slats of magneticmaterialcircumferentially disposed around said armature for magneticattraction toward said poles'upon the passage of electric currentthrough one of said coils, each of said slats circumferentially relievedof material on opposite sidesat opposite ends to provide an air gap ofminimum reluctance for rotation of said armature in one direction uponpassage of electric current through one said coil and for rotation inthe opposite direction upon passage of current through the other saidcoil, two pairs of stationary auxiliary electrical contacts disposedadjacent to said armature mechanically biased to remain closed, a linearcam attached to said armature shaped to open the said electrical contactconnecting the electrical circuit to that coil having the highermagnetic reluctance gap for the direction of rotation chosen, said camshaped to close the electrical circuit of said coil initially having thehigher reluctance magnetic gap upon said armature having rotated half ofthe full angular excursion thereof, the magnetomotive force of the coilthus energized adding to the magnetomotive force of the coil originallyenergized, said slats shaped to remove said high reluctance conditionupon said half rotation of said armature, a spring related to saidarmature to return the same to said initial position for the nextrotative excursion, the direction thereof determined by which of saidcoils is energized; an output shaft, a flatted gear upon said outputshaft, a pawl having a pair of oppositely disposed projections, saidpawl attached to said armature and related to said gear to rotate saidgear a fixed fraction of a revolution, one said pawl projectionpositioned to rotate said gear upon rotation of said armature in onesaid direction and the other said projection positioned to rotate saidgear upon rotation of said armature in the other said direction; pivotedopposed brake members bearing upon said output shaft, a spring betweensaid members proportioned to provide breaking upon said outputsufficient to prevent rotation thereof except upon rotation of saidflatted gear by a said projection.

References Cited in the file of this patent UNITED STATES PATENTS710,951 Barclay Sept. 27, 1904' 921,046 Wilson May 11, 1909 --1,877,480Osborne Sept. 13, 1932 2,928,916 Bonanno Mar. 15, 1960 3,001,107 RhodesSept. 19, 1961 FOREIGN PATENTS 414,688 Great Britain July 30, 1934'

1. IN A DEVICE HAVING AN ARMATURE AND A MAGNETIC STRUCTURE INTERNALTHERETO FOR ROTATION OF SAID ARMATURE BY MAGNETIC FORCE TO A TERMINALAMPLITUDE, FIRST MEANS FOR INCREASING THE TORQUE UPON SAID ARMATURE ATSAID TERMINAL AMPLITUDE COMPRISING, PLURAL SECOND MEANS DISPOSED UPONSAID MAGNETIC STRUCTURE FOR PROVIDING MAGNETIC FORCE, THIRD MEANS TOENERGIZE A SECOND MEANS, AND FOURTH MEANS MECHANICALLY RELATED TO SAIDARMATURE TO ENERGIZE AN ADDITIONAL SAID SECOND MEANS UPON ROTATION OFSAID ARMATURE SUBSTANTIALLY HALF OF SAID TERMINAL AMPLITUDE OF ROTATION.